Chaos in the fractional-order Volta’s system: modeling and simulation

This paper deals with a new fractional-order chaotic system. It is based on the concept of Volta’s system, where the mathematical model of Volta’s system contains fractional-order derivatives. This system has simple structure and can display a double-scroll attractor. The behavior of the integer-order and the fractional-order Volta’s system with total order less than three which exhibits chaos is presented as well. Computer simulations are cross-verified by the numerical calculation and the Matlab/Simulink models.     

Cubic β-Fe2O3 as the product of the thermal decomposition of Fe2(SO4)3

Hyperfine Interactions - The thermal decomposition of Fe2(SO4)3 in air has been investigated using transmission Mössbauer spectroscopy, CEMS and X-ray powder diffraction. The hexagonal...     

Contractible subgraphs, Thomassen’s conjecture and the dominating cycle conjecture for snarks

We show that the conjectures by Matthews and Sumner (every 4-connected claw-free graph is Hamiltonian), by Thomassen (every 4-connected line graph is Hamiltonian) and by Fleischner (every cyclically 4-edge-connected cubic graph has either a 3-edge-coloring or a dominating cycle), which are known to be equivalent, are equivalent to the statement that every snark (i.e. a cyclically 4-edge-connected cubic graph of girth at least five that is not 3-edge-colorable) has a dominating cycle.We use a refinement of the contractibility technique which was introduced by Ryjá?ek and Schelp in 2003 as a common generalization and strengthening of the reduction techniques by Catlin and Veldman and of the closure concept introduced by Ryjá?ek in 1997.     

HPLC and RIA procedure for cyclosporine A determination compared with clinical background

Summary The aim of our study was to monitor Cyclosporine A (CA) during a long-term period and to determine whether the whole-blood levels, estimated by HPLC and radio-immunoassay (RIA), provide a relevant indicator of the toxic effect of CA, of the interference of endogenous substances with CA and of interactions of erythromycin and ketoconazole with CA metabolims. The ratios of CA concentrations, estimated by RIA and by HPLC were calculated in order to analyse changes in CA metabolism. A decrease in this ratio was observed in these patients during periods of erythromycin and ketoconazole therapy deteriorating hepatic function. We observed unusual higher CA concentrations measured by HPLC compared with RIA in heart transplant patient with marked renal insiffuciency after one-year follow-up period of treatment of CA. The comparison of CA whole-blood levels estimated using HPLC and RIA makes it possible to analyse the individual biotransformation of CA to its metabolites, and interference of endogenous substance in special clinical situations.     

On line shape analysis in X-ray photoelectron spectroscopy

Any solid state X-ray photoelectron spectrum (XPS) contains contributions due to multiple inelastic scattering in the bulk, surface excitations, energy losses originating from the screening of the final state hole (intrinsic losses), and, for non-monochromatized incident radiation, ghost lines originating from the X-ray satellites. In the present paper it is shown how all these contributions can be consecutively removed from an experimental spectrum employing a single general deconvolution procedure. Application of this method is possible whenever the contributions mentioned above are uncorrelated. It is shown that this is usually true in XPS to a good approximation. The method is illustrated on experimental non-monochromatized MgK spectra of Au acquired at different detection angles but for the same angle of incidence of the X-rays.     

The synthesis and characterisation of an expansive additive for M-type cements

The expansion effect of laboratory-prepared expansive additives for M-type expansive cement was investigated at the early stage of hydration by the multicell isoperibolic calorimeter and volumetric technique based on Archimedes’ principle. The relative volume changes and heat released during hydration are strongly affected by the content of lime in the expansive additive due to the influence of CaO on the kinetics and mechanism of formation of ettringite. The increasing content of lime favours the formation of monosulphate and its later transformation to ettringite generating expansion stress. The effect of expansive additive on the behaviour of mortar samples was measured as linear elongation of test blocks using Graf-Kaufman dilatometer. Lower or higher content of lime in expansion additive slightly decreases the 7th-day compressive and flexural strength of samples while this effect is negligible for expansive additive with nominal composition of ettringite.     

Rough surface scattering simulations using graphics cards

In this article we present results of rough surface scattering calculations using a graphical processing unit implementation of the Finite Difference in Time Domain algorithm. Numerical results are compared to real measurements and computational performance is compared to computer processor implementation of the same algorithm. As a basis for computations, atomic force microscope measurements of surface morphology are used. It is shown that the graphical processing unit capabilities can be used to speedup presented computationally demanding algorithms without loss of precision.